Process and apparatus for the production of glycerol dichlorohydrin

ABSTRACT

Glycerol dichlorohydrin is prepared by dissolving allyl chloride vapor in an upwardly flowing aqueous stream, dissolving chlorine gas in a separate second upwardly flowing aqueous stream to form a hypochlorous acid solution, mixing the two streams and flowing them downwardly in a reaction column where they react to form glycerol dichlorohydrin.

United States Patent 1 Yamamoto et a1.

1111 3,859,367 [451 Jan. 7, 1975 PROCESS AND APPARATUS FOR THE PRODUCTION OF GLYCEROL DICHLOROHYDRIN [75] Inventors: Hiroaki Yamamotoj Hideo Harada;

Hiroshi Miyaoka; Minoru Tanaka; Osamu Kubota; Shizuo Nakamura; Yasusi Nakamura, all of Tokyo, 'Japan [73] Assignee: Asahidenka Kogyo Kabushiki Kaisha, Tokyo, Japan 22 Filed: Jan. 5, 1972 [21] Appl. No.: 215,564

Related US. Application Data [63] Continuation-impart of Ser. No. 867,635, Oct. 20,

1969, abandoned.

[30] Foreign Application Priority Data Oct. 23, 1968 Japan Oct. 23, 1968 Japan 43-77202 v [52] US. Cl 260/633, 23/283, 23/284,

23/285, 260/614 R, 260/652 R [51] Int. Cl. C07c 31/34 [58] Field of Search 260/633, 634

Primary ExaminerH0ward T. Mars Attorney, Agent, or FirmWoodhams, Blanchard & Flynn [57] ABSTRACT Glycerol dichlorohydrin is prepared by dissolving allyl chloride vapor in an upwardly flowing aqueous stream, dissolving chlorine gas in a separate second upwardly flowing aqueous stream to form a hypochlorous acid solution, mixing the two streams and flowing them downwardly in a reaction column where they react to form glycerol dichlorohydrin.

2 Claims, 24 Drawing Figures PATENTEDJAN mrs 315359.367

PATENTEUJAN 11915 $859,367-

sum 5 or 7 FIG. I? FIG. l8

M/Mm MAM/m 06AM Maw-"4 57/15/10 #4/ 44 454 WWW MIA/14am A VORNEYS PROCESS AND APPARATUS FOR THE PRODUCTION OF GLYCEROL DICHLOROHYDRIN cRoss REFERENCE TO RELATED APPLICATIONS This .application is a continuation-impart of our copending application Ser. No. 867,635 filed Oct. 20, 1969 now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a process and apparatus for continuously producing glycerol dichlorohydrin.

2. Description of the Prior Art It is known that, when allyl chloride is caused to react with chlorine in the presence of water, glycerol dichlorohydrin comprising 1,3- and 1,2-isomers will be obtained in accord with the following equation:

()IIr-CII-CIIZ H01 7' omzoir-cinci 012+ 1n0 c1 II Cl c moIr-om H01 01 Cl 611 (I) However, generally, in this and similar chlorohydrination systems, competing secondary reactions occur producing byproducts such as 1,2,3-trichloropropane and tetrachloropropyl ether according to the following equations:

1 C1 C1 A (II) ((EHz-(EH-CHz) O HCI C1 C1 2 (III) and the yield of glycerol dichlorohydrin has been industrially unacceptably low.

There is also known a process for continuously producing glycerol dichlorohydrin by introducing gaseous allyl chloride into an environment, such as a vertical reaction column, charged with chlorine water. In this case, the yield of glycerol dichlorohydrin has been industrially unacceptably low.

Furthermore, when operating these prior processes so as to favor the production of a product solution of glycerol dichlorohydrin of greater than 6% -w/w concentration, the yield is further reduced.

rectly into the charged ethylene and to introduce ethyl-' ene into the chlorine water. As it would cause the introduction of allyl chloride directly into chlorine water, this apparatus is not satisfactory forthe production of glycerol dichlorohydrin by the process involving equation (I) above.

SUMMARY OF THE INVENTION We have discovered that the production of glycerol dichlorohydrin by the process of equation (I) above is readily feasible with a minimum of by-product formation and at solution concentrations of 4 to 6% and higher with a minimum of by-product formation. This desirable result is produced by the novel continuous cyclic process of the reaction of (l allyl chloride solution obtained by dissolving allyl chloride vapor in a circulat: ing aqueous medium, with (2) hypochlorous acid aqueous solution obtained by dissolving chlorine gas in a circulating aqueous medium, in which a circulating aqueous medium is continuously circulated in a reaction system due to the gas lift effect produced by the introduction of chlorine gas and allyl chloride vapor into the aqueous medium, the reaction system having at least two upward flow columns which comprise at least one chlorine dissolving column and at least one allyl chloride dissolving column, a downward flow reaction column connected at its upward and lower ends to the upper and lower ends of the upward flow columns, said process comprising the following steps:

flowing a portion of the circulating aqueous medium upwardly through said chlorine dissolving column and introducing chlorine gas into the circulating aqueous medium in the lower part of said chlorine dissolving column at a volumetric (m rate, per unit crosssectional area (m) of the chlorine dissolving column, per unit time (hour) in the range. of from about 50 m /m /hour to about 300 m /m /hour to dissolve the introduced chlorine gas in the circulating aqueous medium to produce a hypochlorous acid solution free of chlorine gas bubbles;

flowing the remainder of the circulating aqueous medium upwardly through said allyl chloride dissolving column and introducing allyl chloride vapor into the circulating aqueous medium in the lower part of said allyl chloride dissolving column at a volumetric (m rate, per unit cross-sectional are (m of the allyl chloride dissolving column, per unit time (hour), in the range of from about 50 m /m lhour to about 300 m /m /hour to dissolve the. introduced allyl chloride vapor in the circulating aqueous medium to produce an allyl chloride solution free of allyl chloride bubbles, the rates of introducingchlorine gas and allyl chloride vapor being regulated to maintain the molar ratio of allyl chloride/chlorine added to the aqueous medium between about 0.97 and 1.03 to 1.0;

introducing water into the circulating aqueous medium;

flowing said hypochlorous acid solution and said allyl chloride solution exiting from the upper ends of said upward flow columns into the upper end of said downward flow column and thence downwardly therein to effect mixing and reaction thereof, with the temperature being maintained in the range of from about 45C. to about 90C. to produce glycerol dichlorohydrin solution;

withdrawing from the reaction system a part of said glycerol dichlorohydrin solution consisting essentially of glycerol dichlorohydrin, hydrochloric acid and water for recovery of glycerol dichlorohydrin therefrom; and

flowing the remainder of said glycerol dichlorohydrin solution as the circulating aqueous medium to the lower ends of said chlorine dissolving column and said allyl chloride dissolving column. I

This processaffords the production of glycerol dichlorohydrin at a high yield and with greatly minimized production of such by-products as trichloropropane. It

further affords an economically advantageous process for continuously producing glycerol dichlorohydrin at high yield and high concentration, which can be carried out in a simple form of apparatus not even requiring such circulating means as an agitator or a pump.

The circulating aqueous medium in the steps specified above in the process of this invention has the following character:

I. The circulating aqueous medium at the upper end of the chlorine dissolving column consists essentially of hypochlorous acid, glycerol dichlorohydrin, hydrochloric acid and water.

2. The circulating aqueous medium at the upper end of the allyl chloride dissolving column consists essentially of dissolved allyl chloride, glycerol dichlorohydrin, hydrochloric acid and water.

3. The circulating aqueous medium at the lower ends of the downward flow column consists essentially of glycerol dichlorohydrin, hydrochloric acid and water.

4. The circulating aqueous medium at the lower ends of-the chlorine dissolving column and the allyl chloride dissolving column consists essentially of glycerol dichlorohydrin, hydrochloric acid and water.

A minor amount of unreacted allyl chloride solution may be present in the circulating aqueous medium entering the upflow columns at the position (4) above, but the amount thereof is less than 0.05% by weight of the circulating aqueous medium. Similarly a minor amount of unreacted hypochlorous acid solution may also be present in the medium at this time, but the amount of available chlorine is less than 0.05%, more preferably less than 0.02%, by weight of the circulating aqueous medium.

The reacting zone of the circulating system comprises the region from the upper ends of the two dissolving columns, extending downwardly into the downward flow column. By the time the circulating stream has reached the end of the downward flow column, the reaction has been substantially completed. v The aboveprocess of conducting the reaction between an allyl chloride solution and a hypochlorous acid solution features circulation of the solutions through the dissolving paths and subsequent reacting path by taking advantage of the gas lift effect produced by introducing the allyl chloride vapor and the gaseous chlorine. In order to produce glycerol dichlorohydrin continuously by reacting allyl chloride with chlorine in each other by upperconnecting parts (conduits or passages) and lower connecting parts (conduits or passages) so that the reaction mixture may circulate through'th e reaction apparatus. The upward flow columns comprise at least one allyl chloride vapour dissolving column and at least one chlorine gas dissolving column and these columns are arranged substantially parallel with each other and are separated from each other to prevent substantially allyl chloride vapour bubbles and chlorine gas bubblesfrom contacting or mixing. The chlorine gas dissolving column has a means for introducing chlorine gas into the circulating aqueous mixture at a lower part of said chlorinedissolving column to produce a hypochlorous acid solution. The allyl chloride vapour dissolving column has a means for introducing allyl chloride vapour into the circulating aqueous mixture at a lower part of said allyl chloride dissolving column to produce an allyl chloride solution.

The reaction apparatus has at least one water introducously through said means for introducing chlorine gas.

Allyl chloride vapour is introduced continuously through said means for introducing allyl chloride vapour. The hypochlorous acid solution and the allyl chloride solution are mixed in the upper connecting part and are reacted in the upper connecting part or downward flow column to produce glyceroldichlorohydrin solution. Also water is introduced continuously into the reaction mixture and the produced glycerol dichlorohydrin is discharged continuously and, ifnecessary, excess gas is discharged. v

The term excess gas refers to gas which is in excess of the saturation point in solubility, and therefore does not refer to unreacted allyl chloride or chlorine, since these substances are not present as gases (bubbles of gas) when the two reacting solutions are mixed. Discharge of gases such'as air, carbon dioxide and nitrogen gas is effected. These gases are present in the allyl chloride and the chlorine gas feeds as impurities, and nitrogen or other nonreactive carrier gas enters the appara: tus for cleaning and stripping purposes, and the residual gas is to be vented at the discharge point. Discharge means is also needed to vent excess amounts 'of allyl chloride or chlorine that may be introduced accidentally into the apparatus.

The vents 10 in FIGS. 1-24, which are described I more fully below, are provided so that the waste gas, such as air and carbon dioxide gas, which is commonly present in allyl chloride vapour or/and chlorine gas as impurities can be vented, or gas accidentally introduced in the circulating aqueous mixture. The 'vent. 10 in FIG. 24 is provided so that the nonreactive carrier gas, such as nitrogen gas, which is blown into the circulating aqueous mixture to strip or'remove the unreacted dissolved component such as allyl chloride'can be discharged. Inthe process of this invention, a small stoichiometric excess of allyl chloride is fed in, but it is dissolved in water to produce an allyl chloride solution free of allyl chloride vapour bubbles at the upper end of the allyl chloride dissolving column, since the allyl chloride vapour has high solubility in water.

In the reaction apparatus to be used in the process of the present invention, the sum of the cross-sectional area(s) of the downward flow column (s)I should be made equal to or larger than the sum of the crosssectional area(s) of the allyl chloride vapour dissolving column(s) and the cross-sectional area(s) of the chlorine gas dissolving column(s).

The upward flowcolumns and the downward flow column(s) of the invention are generally constructed as independent columns. However, the upward flow col-' umns and (or) the downward flow column(s) can be constructed by dividing one column or a tube inserted therein vertically with separating means, such as separating plates, into two or more parts which correspond to the upward flow column and downward flow column.

In an embodiment of the invention, the downward flow column and the upward flow columns are constructed by inserting an inner tube into an outer tube so as to form two parts composed of (1) an outside space formed between the inner wall of said outer tube and the outerwall of the inner tube and (2) the inside space of the inner tube, and separating the outside (or inside) space by a vertical separating plate or barrier into two parts, and these three parts constitute the two upward flow columns and a downward flow column. In some embodiments of the present invention, the upward flow columns are constructed by dividing a column vertically by abarrier or separating wall into two parts which constitute an allyl chloride dissolving column and a chlorine dissolving column, or by inserting an inner tube into an outer tube so as to form two parts which comprise, respectively, an allyl chloride dissolving column and a chlorine dissolving column.

Further, in some embodiments of the present invention described above, the upper part of the barrier or the inserted inside tube wall, which separate the upward flow columns, can have small holes, slits or can be constructed of a lath as a metal lath (expanded metal) or wire lath so that the transfer of the gases or gas bubbles is prevented, but a part of the reacting solution can be transferred between them.

The cross-sections of the allyl chloride dissolving'column and the chlorine dissolving column and the down ward flow column can be made in any shape such as, for example, a circular or semicircular shape. However, it is preferable that they are made in a circular or semicircular shape or any shape similar to them.

Further, in feeding or introducing allyl chloride and chlorine to the reaction apparatus, it is preferable to feed them in a finely dispersed state byv using, for example, nozzles or such gas dispersing plates asglass filters.

In a preferred embodiment of the present invention, means for blowing an nonreactive gas is provided below the upper surface of the reaction mixture in the downward flow column and/or the upper connecting means to strip or remove excess raw'materials from the reaction mixture, such as allyl chloride. It is most preferable to use a nitrogen gas for the nonreactive gas.

The means for blowing in the nonreactive gas may be constructed, for example, by a porous tube positioned near the uppersurface of the reaction mixture. It is preferable thatthe gas discharged from the reaction apparatus is fed to a washer, is washed with water to remove the excess allyl chloride as a solution and the obtained allyl chloride aqueous solution is cyclically reacted by feeding the solution to the lower part of the allyl chloride dissolving column. n

For example, the above mentioned nonreactive gas washer can be formed by a packed tower. The discharged gas containing allyl chloride vapour and nitrochloride is stripped as an aqueous solution, which is discharged from the bottom of the washer, and washed nitrogen is discharged from the top of the washer. It is preferable that the packings are made of porcelain and are in the form of Raschig rings.

A further preferred, embodiment of the present invention comprises continuously conducting the reaction of allyl chloride with hypochlorous acid while making the reaction mixture circulate by the gas lift effect produced by introducing allyl chloride vapour and chlorine gas into an aqueous reaction mixture in the apparatus wherein, in order to continuously produceglycerol dichlorohydrin, a downward flow column is connected with at least four upward flow columns by upper connecting parts and lower connecting parts so that the reaction solution may circulate through the reaction apparatus. About half of the upward flow columns constitute allyl chloride dissolving columns and the remainder of them constitute chlorine dissolving columns. Allyl chloride vapour introducing means are provided in the lower parts of the allyl chloride dissolving columns. Chlorine gas introducing means are provided in the lower parts of the allyl chloride dissolving columns. The respective upward flow columns are connected in a substantially tangential direction to the upper part of the side wall of said downward flow column by the above mentioned upper connecting parts and, further, a water introducing means, reaction mixture discharging means and, if necessary, excess gas (or gases) withdrawing means are provided (preferably the allyl chloride dissolving columns and chlorine dis solving columns are arranged alternately and in parallel). Chlorine gas is introduced continuously through said chlorine gas introducing means into the reaction mixture to produce hypochlorous acid solution. Allyl chloride vapour is introduced continuously through said allyl chloride vapour introducing means into the reaction mixture to produce allyl chloride solution. Water is introduced continuously to the reaction mixture. The reaction mixture can flow upwardly in the upward flow columns and can flow downwardly while forming a swirling stream in the downward flow column.

Further, in the process of the present invention, it is permitted, within the scope of the present invention, to use a raw material gas of an industrial purity. Further, the raw material can be preheated and the reaction apparatus can be heated or cooled as desired. Any known conventional-method can be used to separate'and recover the desired component (glycerol dichlorohydrin) from the reaction product mixture.

, In the process of the present invention, the reaction temperature can be a temperature at which allyl chloride will not condense, such as 45 to 90C., preferably 55 to C. For this purpose, it is preferable to provide the reaction apparatus with a jacket for adjusting the temperature.

Further, the rates at which allyl chloride and chlorine are fed to the reaction system may be such that the mol ratio of allyl chloride/chlorine can be in the range of 0.97 1.03/1, preferably 1.000 1.005/1.

Further, it is preferable that the feeding concentration of the raw material gases, that is, the ratio of the (l) totalfeeding amount of the allyl chloride and chlorine, per unit time, to (2) the amount of water fed in,

" (hour), is in the range of 50 to 300 m /m /hour.

The-reaction apparatus to be used in the process of the present invention may be of sufficient height to dissolve the fed raw material gases in water while they flow upwardly in the respective dissolving columns (or parts) and may be generally from 2 to 8 m., preferably 4 to m., in height.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of reaction apparatus to be used in the process of the present invention shall be explained with reference to FIGS. 1 to 24 in the accompanying drawings.

FIG. 1 is a schematic vertical section view of a reaction apparatus wherein the upward flow columns are formed by two columns arranged inparallel branches soas to comprise, respectively, an allyl chloride dissolving column and a chlorine dissolving column.

FIG. 2 is a schematic vertical section view of a reaction apparatus wherein three columns or towers are arranged in parallel and connected so that an allyl chloride dissolving column and a chlorine dissolving column are, respectively, on the left and right and a downward flow column is in the middle. 1

FIG. 3 is a partly cut-away perspective view ofa reaction apparatus wherein the downward flow column and the upward flow columns are constructed by inserting an .inside tubeinto an outside tube, and separating the outside space/formed between the inner wall of said outside tube and the outer wall of said inside tube by vertical-separating barriers into two columns forming", respectively, an allyl chloride dissolving column and a chlorine dissolving column, and the inside spaceof the .inside tube constitutes a downward flow column.

FIG. 4 is a schematic vertical section view of the reaction apparatus shown in FIG. 3.

FIG. 5 is a cross-sectional view of the reaction apparatus shown in FIG. 3. r v

FIG. 6 is a partly cut-away perspective view of a reaction apparatus wherein the downward flow columnand FIG. 10 is a schematic, cross-sectional view of the re I action apparatus shown in FIG. 9.

FIG. 11 is a schematic vertical section view of a reaction apparatus comprising a downward flow column and the upward flow'columns are constructed by dividing a column with a vertical barrier, of which' the' upper half is constructed of titanium lath (of about 30 meshes), into two parts to form, respectively, an allyl chloride dissolving part and a chlorine dissolving part, which parts are connected with each other by upper and lower connecting parts. b

FIG. 12 is a schematic vertical sectional view taken on line XII-XII in FIG. ll.

FIG. 13 is a schematic sectional view taken on line XIII-XIII in FIG. ll.-

FIG. 14 is a partly cut-away perspective view' of a reaction apparatus comprising a downward flow column and in which the upward flow columns are constructed action apparatus comprising a-downward flow column and in which. theupward flow columns'are constructed by inserting an inside column into the outside column so as to divide the outside column into two parts to form, respectively, an allyl chloride dissolving part and a chlorine dissolving part, which parts are connected (or joined) with the downward flow column by upper and lower connecting conduits, and said inside column has many smallcommunicating holes in the uppper half of it. FIG. 18 is a schematic vertical section action apparatus shown in FIG. 17.

FIG. 19 is a'schematic cross-sectional view of the reaction apparatus shown in FIG. 17.

FIG. 20 is a schematic vertical section view of a reaction apparatus comprising a downward flow column and in which the upward columns are constructed by insertingan inside column into an outside column so as to divide the outside column into two parts to form, respectively, an allyl chloride dissolving part and a chlorine dissolving part, which parts are connected with the view of the redownward flow column by upper and lower connecting F IG. 8 is a schematic cross-sectional view of the reaction apparatus shown in FIG. 6.

FIG. 9 is a schematic vertical section view of a reaction apparatus comprising a downward flow column and in which the upward flow columns are constructed by separating a column with a vertical separating barrier into two parts to form, respectively, an allyl chloride dissolving part and a chlorine dissolving part,

which parts are connected with each other by upper and lower connecting parts.

conduits, and the inside column is constructed of a titanium lath (of about 30 mesh) in the upper half of it.

FIG. 21 is a schematic cross-sectional view of the reaction apparatus shown in FIG. 20.

FIG. 22 is a partly cut-away elevational view of a reaction apparatus wherein theupward flow columns are comprised of four columns, two of them are allylchlO- ride dissolving parts and the remaining two are chlorine dissolving parts, and the four upward flow columns are connected in a tangential direction to the upper and lower parts of the side wall of a downward flow column by upper and lower connecting conduits.

FIG. 23 is a schematic section view on line XXIII- XXIII in FIG. 22. FIG. 24 is a partly cut-away view of a reaction apparatus wherein the upward flow columns are formed of two columns arranged in parallel branches so as to form, respectively, an allyl chloride dissolving column and a chlorine dissolving column, and a nonreactive gas blowing means is provided below the upper surface of the reaction mixture of the downward flow column.

In FIG. 1, is an allyl chloride dissolving column and 6 is a chlorine dissolving column. Allyl chloride vapour is fed or introduced through an allyl chloride vapour introducing means 1 at a lower part of the column 5 and chlorine gas is fed or introduced through a chlorine gas introducing means 2 at a lower part of the column 6.

Allyl chloride dissolving column 5 and chlorine dissolving column 6 and a downward flow column 7 are connected with each other by an upper connecting part or conduit 8 and a lower connecting part or conduit 9. Water is fed or introduced through a'water introducing means 3 in the lower connecting part 9. The introduced allyl chloride vapour bubbles and the introduced chlorine gas'bubbles rise through, respectively, the allyl chloride dissolving column 5 and the chlorine dissolving column 6 due to their buoyancy and are dissolved in the circulating aqueous mixture in the columns and chlorine is converted to hypochlorous acid. The allyl chloride solution and hypochlorous acid solution are mixed together in the upper connecting means 8, and the thus obtained reaction mixture flows downwardly through the downward flow column 7 while reacting to produce glycerol dichlorohydrin solution. The

obtained glycerol dichlorohydrin solution is discharged continuously from the apparatusthrough a reaction product outlet port as the glycerol dichlorohydriin discharging means 4 in the lower connecting part 9. The upper connecting part 8 is provided with a vent constituted as a waste gas discharging means 10 so that the waste gas or excess gas may be vented (or discharged), if necessary. 11 is a jacket for adjusting the reaction temperature.

The same numerals 1 to 10 given in the above mentioned FIG. 1 respectively are used to identify corresponding parts in the following FIGS. 2 to24.

In FIG. 2, water is fed or introduced through an inlet port constituted asa water introducing means 3 in a lower connecting part 9, and the obtained glycerol dichlorohydrin solution is discharged continuously from the apparatus through a reaction product outlet port constituted as a glycerol dichlorohydrin solution discharging means 4 in the lower part of the downward flow column 7. The same operation and reaction, as are explained with reference to FIG. 1, are carried out in the case of FIG. 2.

In FIGS. 3 to 5, the inside tube 13 is inserted into and positioned by fixing means in the outside tube 12, and inside tube 13 is shorter than the outside tube 12. The space between the inner wall of outside tube 12 and the outer wall of inside tube 13 is divided with two vertical inlet port constituted as an allyl chloride introducing means 1 at a lower part of the allyl chloride dissolving column 5 and chlorine gas is fed or introduced through an inlet port 2 at a lower part of the chlorine dissolving column 6. Water is fed or introduced through an inlet port constituted as a water introducing means 3 in the lower connecting part 9.

The same operation and reaction as are explained above with reference to FIG. 1 are carried out in the case of FIGS. 3 to 5.

In FIGS-6 to 8, the inside tube 13 is inserted and positioned in the outside tube 12, and the inside tube 13 is shorter than the outside tube 12. The inside space of the inside tube 13 is divided with a vertical separating barrier 14 into two parts to be, respectively, an allyl chloride dissolving column 5 and a chlorine dissolving colummn 6. The space between the inner wall of the outside tube 12 and the outer wall of the inside tube 13 constitutes a downward flow column 7.

The space between the top wall of the outside tube 12 and the upper edge of the inside tube 13 constitutes an upper connecting part 8, and the space between the bottom wall of outside tube 12 and the lower edge of the inside tube 13 constitutes a lower connecting part 9. Allyl chloride vapour is fed or introduced through an inlet port constituting an allyl chloride introducing means 1 at a lower part of the allyl chloride dissolving column 5 and chlorine gas is fed or introduced through an inlet port constituting a chlorine introducing means 2 at a lower part of the chlorine dissolving column 6. Water is fed or introduced through an inlet port constituting a water introducing means 3 in the lower connecting part 9. And the obtained glycerol dichlorohydrin solution is discharged continuously from the apparatus through a reaction product outlet port 4 in the lower part of the lower connecting part 9. The same operation and reaction as are above explained with reference to FIG. 1 apply in the case of FIGS. 6 to 8.

In FIGS. 9 to 10, the upwardflow columns are constructed by dividing a column 15 with a verticalseparating barrier 14 intotwo parts to form, respectively, an allyl chloride dissolving part5 and a chlorine dissolving part 6. Allyl chloride vapour is fed or introduced through an inlet port 1 at a lower part of the allyl chloride dissolving part 5 and chlorine gas is fed or introduced through an inlet port 2 at a lower part of the chlorine dissolving part 6. Water is fed or introduced through an inlet port 3 in the lower connecting part 9. The obtained glycerol dichlorohydrin solution is discharged continuously from the apparatus through a reaction product outlet port 4 in the lower part of the downward flowing column 7. The same operation and separating barriers Hand 14 into two parts to form,"

titanium lath 14", into two parts to form, respectively,

an allyl chloride dissolving part 5 and a chlorine dissolving part 6. In the upward flow columns divided with the titanium lath 14'', the transferof the gases or gas bubbles is prevented but a part of the reacting solution can be transferred between them.

The same operation and reaction as are explained above with reference to FIG. 1 apply in the case of FIGS. 11 to 13.

. 'In FIGS. 14 to 16, the upward flow columns are constructed by inserting an inside column 17in the outside column 16 so as to divide-the outside column 16 into two parts to be, respectively, an allyl chloride dissolving column and a chlorine dissolving column 6.

.inlet port 3 in the lower connecting part 9. The obtained glycerol dichlorohydrin solution is discharged continuously from the apparatus through a reaction product outlet port 4 in the lower part of the downward flow column'7.'The same operation and reaction as are above explainedwith reference to FIG. 1 apply in the case of FIGS. 14 to 16.

In FIGS. 17 to 19, the upward flow columns are constructed by inserting an inside column 17in the outside column 16 so as to divide the outside column 16 into two parts to be, respectively, an allyl chloride dissolving column. 5 and a chlorine dissolving column 6.

The inside column 17 has many small communicating holes 18 in the upper half of it.

. In the upward flow columns divided with inside column 17 having many small communicating holes 18, the transfer of the gases or gas bubbles is prevented but chloride vapourbubbles and'the introduced chlorine gas bubbles rise through, respectively, allyl chloride dissolving columns 5 and chlorine dissolving columns 6 due to their buoyancy and aredissolved in the circuapart of the reacting solution can be transferred between them.

The sameoperation and reaction as are above ex- "plained witn reference to FIG. 1 apply in the case of FIGS. 17 to 19. I I

In FIGS. 20 to 21, the upward flow columns are constructed by insertingan inside'column 17 in the outside column 16 so as to divide the outside column l6 into two parts to be, respectively, an allylchloridedissolving column 5 and a chlorine dissolving column 6. r

The upper half of the inside column 17 is constructed of titanium lath l4.

In the upward flow columns divided with inside column 17 constructed by titanium lath 14 in the upper half of it, the transfer of the gases or gas bubbles can be prevented but a part of the reacting solution can be transferred between them. The same operation and reaction as'are above explained with reference to FIG. 1

apply' in the case of FIGS. 20 to 21. t p In FIGS. 22 to 23, 5 is an allyl chloride dissolving column, 6 is a chlorine dissolving column and 7 is a downward flow column. Two allyl chloride dissolving columns 5 are connected in a tangential directionto the upper part 20 of the side wallof the downward flow column 7 by the upper connecting conduits 19 and are connected also-in the'tangential direction to the lower part 22 of the side wall of the downward flow column 7 by the lower connecting conduits 21. Also two chlo- ,ward flow column 7 by the lower connecting conduits 24. Water is fed through a water introducing means 3. Allyl chloride vapour is fed or introduced through the .allyl chloride vapour introducing means 1 having the r'ing-shaped nozzles 25, and chlorine gas is fed or introduced through the chlorine gas introducing means 2 having the ring-shaped nozzles 26. The introduced allyl rine dissolving columns'6 are connected in the tang'enthe washer 28 as indicated by'the arrow 33.

lating aqueous'medium in the columns and chlorine is converted tohypochlorous acid. The respective aque-' ous solutions are mixed together in the upper part of the downward flow column 7 and the reaction mixture flows downward while forming a swirling stream to react to produce glycerol dichlorohydrin. The obtained glyceroll'dichlorohydrin solution is discharged continuously from the reaction apparatus through'a reaction product outlet port constituted as glycerol dichlorohydrin discharging means 4. The upper part of the downward flow column 7 is provided with a vent constituted as a waste gas discharging means 10 so that the waste gas or excess gas can be vented (or discharged), if nec-' essary. 7 I

In FIG. 24, 5 is an allyl chloride dissolving column and 6 is a'chlorine dissolving column. Allyl chloride vapour is fed or introduced through an allyl chloride vapour introducing means 1 ata lower part of the column 5 and chlorine gas is fed or introduced through a chlorine gas introdu'cing means 2 at a lower part of the column 6. Allyl chloride dissolving column 5 and a chlorine dissolving c'olumn.6 and a downward flow 'column -7 are connected-with each other by an upper connecting part in the form of a tank 8 and a lower connecting part 9. A nonreactive gas blowing means 27 consisting of a porous tube having a multitude of holes 32 is provided in the lower part'of the tank-shaped upper connecting part 8. Water is fed through a water introducing means 29 provided in the washer 28. The introduced allyl chloride vapour bubbles and the introduced chlorine gas bubbles rise through the allyl chloride dissolving column S' and chlorine dissolving column 6, respectively, due to theirv buoyancy and are dissolved in the circulating'aqueous medium in the columns and chlorine is converted to hypochlorous acid;

The allyl chloride solution and hypochlorous acid solution are mixed together in the upper connecting means 8, and-the thus obtained reaction mixture flows downward through thedownward flow column 7 while reacting to produce glycerol dichlorohydrin solution.

-A-nonreactive gas is fed through the nonreactive gas blowing means 27 provided within the tank-shaped upper connecting part 8 and is blown into'the reaction mixture through the holes 32.

Thus the unreacted component (unreacted excess allyl chloride) in the reaction mixture is stripped (or degassed) and is discharged through the vent 10. The obtained mixture of the unreacted excess allyl chloride and nonreactive gas is introduced into the 'lower part of The washer 28 is'packed with Raschig rings made of porcelain. The discharged gas mixture is made -to .contactcountercurrently with water in the washer 28.

- Allyl chloride is stripped as an aqueous solution and the obtained allyl chloride solution is recycled into the allyl chloride dissolving column 5 as indicated by the arrow 31.

The washed nonreactive gas is discharged from the top of the washer 28 and is fed again to the nonreactive gas blowing means 27 as indicated by the arrow 34. The obtained glycerol dichlorohydrin solution is discharged continuously from the apparatus through a reaction product outlet port constituted as glycerol dichlorohydrin discharging means 4.

In FIGS. 2 to 24, thejacket for adjusting the temperature of the reaction is omitted to simplify the drawings.

The effect of the present invention is to provide a new process wherein allyl chloride and chlorine each dissolve completely in the respective dissolving parts or columns, the reaction between the solutions takes place when they are mixed and flow downwardly so quickly that the production of such by-product as trichloropropane is minimized and glycerol dichlorohydrin' is produced'at a high rate of yield.

Another effect of the present invention is to provide a very economical and advantageous process for continuously producing glycerol dichlorohydrin which can be carried out with'a comparatively simple apparatus without using any stirrer or pump and in which the power cost can be reduced due to the natural circulation of the system.

A further effect of the present invention is to provide a new process for continuously producing glycerol dichlorohydrin wherein a sufficiently high yield can be obtained even in the caseof obtaining glycerol dichlorohydrin ofa high concentration.

EXAMPLE 1 This example was carried out by using a reaction apparatus of the type shown in FIG. 1. The height of the reaction apparatus used in this example was about m. The distance from the allyl chloride and chlorine feeding positions 1 and 2 to the tower top was about 4m. The column diameter of each of the allyl chloride dissolving column 5 and the chlorine dissolving column 6 was 2.5 cm. (1 inch). The column diameter of the downward flow column 7 was 5 cm. (2 inches). The capacity of the apparatus was about 30 liters.

About 30 liters of a solution of 4% glycerol dichlorohydrin were charged in the above mentioned reaction apparatus and were warmed to about 60C. with the warming jacket 11.

Then, while keeping the liquid temperature at 60C., there were fed into the apparatus continuously an allyl chloride vapor at a feed rate of 195.0 g./hr. while being finely dispersed with a glass filter, a chlorine gas at a feed rate of 180.0 g./hr. while being also finely dispersed in the same manner and water at a feed rate of 8135 g./hr. In such case, the mol ratio of allyl chloride/- chlorine was about 1.005.

Thus a solution of about 4% glycerol dichlorohydrin was continuously produced.

Theyields of dichlorohydrin and the yields of the byproduct in such case are shown in the following Table l.

The yield was calculated as follows: Glycerol dichlorohydrin yield in based on allyl chloride X/Y X 100. j X The'glycerol dichlorohydrin produced in moles/- hour. Y The allyl chloride feed in moles/hour. This methodof glycerol dichlorohydrin yield calculation is used in all the examples in this application.

EXAMPLES 2 and 3 A solution of each of 5.5% and 6.5% glycerol dichlorohydrin was continuously produced as in Example 1 by using the same reaction apparatus as was used in the above mentioned Example 1. The results are shown in Table l.

Table l Examples 1 2 3 Figure I A.C. solution Cl, solution Reaction apparatus Reaction conditions A.C. feed in g./hr. 195 I I95 CI, feed in g./hr. I80 180 Produced D.C.l-I. concentra- 4 5.5 6.5 tion in D.C.l-I. yield in on A.C. 98.3 95.0 90.2 D.C.l-l. yield in on CI, 98.0 93.7 90.3 Total yield of T.C.P. and 0.6 L8 2.7 E. in on Cl,

Concentration of AC. in trace 0.0I 0.01 Concentration of Cl, in trace trace trace Note In Table l above. the symbols of A.C., Cl,. D.C.H.. T.C.P. and E. mean respectively as follows: A.C. Allyl chloride Cl, Chlorine D.C.H. Glycerol dichlorohydrin T.C.P. Trichloropropane E. :Tetrachloropropyl ether Concentrations ot'A.C. and Cl, mean the concentration of A.C. and CI, in the circulating aqueous mixture at the position of 9 in FIG. 1

EXAMPLE 4 cm. (1 inch). The column diameter of the downward flow column 7 was 7.5 cm. (3 inches). The capacity of the apparatus was about 40 liters.

About 40 liters of a solution of 4% glycerol dichlorohydrin were charged in the above mentioned reaction apparatus and were warmed to about 60C. with the warming jacket. I

Then, while keeping the liquid temperature at 60C., there were fed continuously an allyl chloride vapor. at a feed rate of a total of 390 g./hr. while being finely dispersed, a chlorine gas at a feedrate of a total of 360 g./hr. while being also finely dispersed in the same manner and water at a feed rate of 16270 g./hr. In such case, the mol ratio of allyl chloride/chlorine was about 1.005.

Thus a solution of about 4% glycerol dichlorohydrin was continuously produced.

The yield of glycerol dichlorohydrin and the yield of the by-product in such case are shown in the following Table 2. That is to say, glycerol dichlorohydrin was obtained at a high yield.

COMPARATIVE EXAMPLES l and 2 A solution of 4% glycerol dichlorohydrin was continuously produced by making the mol ratio of allyl chloride/chlorine, respectively, of 1.06 and 0.94 as in Example 4 by using the same reaction apparatus as was used in the above mentioned Example 4.

' position of 24 in FIG. 22

'15 The results are shown in Table 2.'

EXAMPLES and 6 A solution ofeach of 5.0% and 6.0% glycerol dichlo- 16 EXAMPLES 8 and 9 A solution of 4.5% glycerol dichlorohydrin was con-.

Note Concentration of'A.C. and Cl,

. XAMPLE 7 AND COMPARATIVE EXAMPLE 3 This examples was carried out by using a reaction apparatus of the type shown in FIG. 24. The height of the reaction apparatus used in this example was about 8m. The column diameter of each of the allyl chloride dissolving column 5 and chlorine dissolving column 6 was .2.5 cm. The column diameter of the downward flow column 7 was 5 cm.

A solution .of 4% glycerol dichlorohydrin was charged, in the above mentioned reaction apparatus and was warmed -to about; 60C. with the warming jacket.

Then while keeping the liquid temperature at 60C., an allyl chloride vapor and chlorine gas were fed continuously while being respectively finely dispersed with glass filters.

On the other hand, water was fed continuously through the water introducing means 29 and a nitrogen gas was fed through the nonreactive gas blowing means 27. Thus the reaction was conducted to continuously produce a solution of about 4% glycerol dichlorohydrin.

Note Concentration of A.C. and Cl, mean the con centration ol A.C. and Cl, in the circulating aqueous mixture at the position M9 in FIG. 24.

rohydrin was continuously produced as in Example 4 5 P- produced as m ExamPlel by the,same' by using the same reaction apparatus as was used in the giactloln alpparatus as was used m the above memloned above mentioned Example 4. The results are shown in xamp e Table 2. The results are shown in Table 4.

Table 2 7 Comparative Examples Examples 4 5 Reaction apparatus Figure 22 Reaction conditions A.C. solution Cl solution A.C. feed in g./hr. 390 390 390 400 390 Cl, feed in g/hr. 360 360 360 350 385 A.C./Cl; mol ratio 1.005 L005 1.005 1.06 0.94 Produced D.C.H. concen- 4.0 5.0 6.0 4.0 4.0 tration in t D.C.H. yield in on A.C. 98.9 95.5 92.0 87.1 86.2 D.C.H. yield in on cl, 98.7 95.0 91.8 89.3 82.5 Total yield of T.C.P. and 0.5 1.4 2.5 0.6 0.6 E. in on Cl v Concentration of AC. trace trace 0.010 0.02 trace in 7: A Co ricentration of Cl trace trace trace trace 0.02 lll mean the concentration of A.C. and CI, in the circulating aqueous mixture at the Note: Concentration olA.C. and Cl, mean the concentration ol'A.C. and CI, in the circulating aqueous mixture at the position of 9 in FIG. I.

In all Tables, trace means under 0.01%, and Concentration' of Cl, means the concentration of available chlorine in the circulating aqueous mixture.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as folv lows:

l. A continuous cyclic process for producing glycerol dichlorohydrin by the reaction of (l) allyl chloride solution obtained by dissolving allyl chloride. vapor in an aqueous circulating medium, with (2) hypochlorous acid aqueous solution obtained by dissolving chlorine gas in an aqueous circulating medium, in which acirculating aqueous medium is continuously circulated in a reaction system due to the gas lift effect produced by the introduction of chlorine gas and allyl chloride vapor into the circulating aqueous medium, the reaction system having at least two upward flow columns which comprise at least one chlorine dissolving column and at least one allyl chloride'dissolving column, a downward flow reaction column connected at its upper and. lower ends. tothe upper'and lower ends of the upward flow columns respectively, and" in which all reactive contact between allyl chloride and hypochlorous a 1 7 13 g i acid takes place between solution (1) and solution (2), 1.005 to 1.0 and the chlorine gas and allyl chloride said process comprising the following steps? vapor being supplied so as to prevent substantial flowing a portion of the circulating aqueous medium 7 contacting or mixing of allyl chloride vapor bubupwardly through said chlorine dissolving column bl s and hlorine gas bubbles; and lntroduclng Q r gas the Circulating S introducing water into the circulating aqueous meaqueous medium in the lower part of said chlorine dium; v dlssolvmg collfmn I at a "Olumemc Yale, PF flowing said hypochlorous acid solution and said allyl unit cross-sectlonal area (m of the chlorine (11S: chloride solution exiting f the upper ends f solving column, per unit time (hour), in the range of from about 50 m /m /hour to about 300 m /m /hour to dissolve completely'the introduced chlorine gas in the circulating aqueous medium to produce a hypochlorous acid solution;

flowing the remainder of the circulating aqueous medium upwardly through said allyl chloride dis- 15 solving column and introducing allyl chloride v vapor into the circulating aqueous medium in the lower part of said allyl chloride dissolvingrcolumn said downward flow column and thence downwardly therein to effect mixing and reaction thereof, with the temperature being maintained in the range of from 45C. to 90C to produce glycerol dichlorohydrin solution; r

withdrawing from the reaction system a part of said glycerol dichlorohydrin solution; and

flowing the remainder of said glycerol dichlorohydrin at a volumetric (m rate, per unit cross sectional Solution as ciwulalmfi P to the area (m of the allyl chloride dissolving column, w r ends of f f dlssolvmg Column and per unit time (hour), in the range of from about 50 allyl chlol'lde l m to about 300 ma/mfl/hour to dissolve 2. A process according to claim 1, in which said by completely th i t d d ll l hl id vapor i pochlorous acid solution and said allyl chloride soluthe circulating aqueous m diu t produce an ll l tion are introduced in a tangential direction to the chloride solution, the rates of introducing chlorine upper'part of said downward flow column so that they gas and allyl chloride vapor being regulated to form a swirling stream as they flow downwardly maintain .the molar ratio of allyl chloride/chlorine through said downward flow column. added to the aqueous medium between 1.000 and said upward flow columns into the upper end of 

1. A CONTINUOUS CYCLIC PROCESS FOR PRODUCING GLYCEROL DICHLOROHYDRIN BY THE REACTION OF (1) ALLYL CHLORIDE SOLUTION OBTAINED BY DISSOLVING ALLYL CHLORIDE VAPOR INA N AQUEOUS CIRCULATING MEDIUM, WITH (2) HYPOCHLOROUS ACID AQUEOUS SOLUTION OBTAINED BY DISSOLVING CHLORINE GAS IN AN AQUEOUS CIRCULATING MEDIUM, IN WHICH A CIRCULATING AQUEOUS MEDIUM IS CONTINUOUSLY CIRCULATED IN A REACTION SYSTEM DUE TO THE GAS LIFT EFFECT PRODUCED BY THE INTRODUCTION OF CHLORINE GAS AND ALLYL CHLORIDE VAPOR INTO THE CIRCULATING AQUEOUS MEDIUM, THE REACTION SYSTEM HAVING AT LEAST TWO UPWARD FLOW COLUMNS WHICH COMPRISE AT LEAST ONE CHLORINE DISSOLVING COLUMN AND AT LEAST ONE ALLYL CHLORIDE DISSOLVING COLUMN, A DOWNWARD FLOW REACTION COLUMN CONNECTED AT ITS UPPER AND LOWER ENDS TO THE UPPER AND LOWER ENDS OFTHE UPWARD FLOW COLUMNS RESPECTIVELY, AND IN WHICH ALL REACTIVE CONTACT BETWEEN ALLYL CHLORIDE AND HYPOCHLOROUS ACID TAKES PLACE BETWEEN SOLUTION (1) AND SOLUTION (2), SAID PROCESS COMPRISING THE FOLLOWING STEPS: FLOWING A PORTION OF THE CIRCULATING AQUEOUS MEDIUM UPWARDLY THROUGH SAID CHLORINE DISSOLVING COLUMN AND INTRODUCING CHLORINE GAS INTO THE CIRCULATING AQUEOUS MEDIUM IN THE LOWER PART OF SAID CHLORINE DISSOLVING COLUMN AT A VOLUMETRIC (M3) RATE, PER UNIT CROSS-SECTIONAL AREA (M2) OF THE CHLORINE DISSOLVING COLUMN, PER UNIT TIME (HOUR), IN THE RANGE OF FROM ABOUT 50 M3/M2/HOUR TO ABOUT 300 M3/M2/HOUR TO DISSOLVE COMPLETELY THE INTRODUCED CHLORINE GAS IN THE CIRCULATING AQUEOUS MEDIUM TO PRODUCE A HYPOCHLOROUS ACID SOLUTION; FLOWING THE REMAINDER OF THE CIRCULATING AQUEOUS MEDIUM UPWARDLY THROUGH SAID ALLYL CHLORIDE DISSOLVING COLUMN AND INTRODUCING ALLYL CHLORIDE VAPOR INTO THE CIRCULATING AQUEOUS MEDIUM IN THE LOWER PART OF SAID ALLYL CHLORIDE DISSOLVING COLUMN AT A VOLMETRIC (M3) RATE, PER UNIT CROSS-SECTIONAL AREA (M2) OF THE ALLYL CHLORIDE DISSOLVING COLUMN, PER UNIT TIME (HOUR), IN THE RANGE OF FROM ABOUT 50 M3/M2/HOUR TO ABOUT 300M3 M3/M2/HOUR TO DISSOLVE COMPLETELY THE INTRODUCED ALLYL CHLORIDE VAPOR IN THE CIRCULATING AQUEOUS MEDIUM TO PRODUCE AN ALLYL CHLORIDE SOLUTION, THE RATES OF INTRODUING CHLORINE GAS AND ALLYL CHLORIDE VAPOR BEING REGULATED TO MAINTAIN THE MOLAR RATIO OF ALLYL CHLORIDE/CHLORINE ADDED TO THE AQUEOUS MEDIUM BETWEEN 1.000 AND 1.005 TO 1.0 AND THE CHLORINE GAS AND ALLYL CHLORIDE VAPOR BEING SUPPLIED SO AS TO PREVENT SUBSTANTIAL CONTACTING OR MIXING OF ALLYL CHLORIDE VAPOR BUBBLES AND CHLORINE GAS BUBBLES; INTRODUCING WATER INTO THE CIRCLATING AQUEOUS MEDIUM; FLOWING SAID HYPOCHLOROUS ACID SOLUTION AND SAID ALLYL CHLORIDE SOLUTION EXITING FROM THE UPPER ENDS OF SAID UPWARD FLOW COLUMNS INTO THE UPPER END OF SAID DOWNWARD FLOW COLUMN AND THENCE DOWNWARDLY THEREIN TO EFFECT MIXING AND REACTION THEREOF, WITH THE TEMPERATURE BEING MAINTAINED IN THE RANGE OF FROM 45*C. TO 90*C TO PRODUCE GLYCEROL DICHLOROHYDRIN SOLLUTION; WITHDRAWING FROM THE REACTION SYSTEM A PART OF SAID GLYCEROL DICHLOROHYDRIN SOLUTION; FLOWING THE REMAINDER OF SAID GLYCEROL DICHLOROHYDRIN SOLUTION AS THE CIRCULATING AQUEOUS MEDIUM TO THE LOWER ENDS OF SAID CHLORINE DISSOLVING COLUMN AND SAID ALLYL CHLORIDE DISSOLVING COLUMN.
 2. A process according to claim 1, in which said hypochlorous acid solution and said allyl chloride solution are introduced in a tangential direction to the upper part of said downward flow column so that they form a swirling stream as they flow downwardly through said downward flow column. 